SU687574A1 - Device for measuring the difference between radio pulses phases - Google Patents

Description

The invention relates to a radio metering technique and can be used to measure the phase difference of radio signals in phase systems. A phase meter is known that contains a number of memory devices, to which input signals are input through the keys controlled by the shift register. The shift register controls pulses from a special generator. The frequency of the pulses from the generator is much higher than the frequency of filling of the radio pulses, which allows you to make the required number of samples during the period of filling and record these samples in memory devices. A different shift register is connected to the pulse generator via a frequency divider that controls the operation of the keys located at the output of the memory devices. As a result of reading samples of input signals from the memory devices and their filtering, low-frequency voltages are created with a phase difference equal to the phase difference of the high-frequency radio pulses. . These voltages are applied to a low frequency phase meter, which records the measurement result. The disadvantages of this method are the low speed of the circuit due to the transfer of phase relations to a low frequency, and the greater complexity of the execution of circuits and nodes of the phase meter. The closest in technical essence to the present invention is a device for measuring the phase difference of radio pulses, containing two series-connected phase detectors and paraphase amplifiers, the inputs of the phase detectors are connected via phase-shifting circuits. The disadvantages of this device are the low speed of the measurement process, which is caused by the transfer of phase relations to a low frequency, and the occurrence of errors determined by additional signal processing from the outputs of the phase detectors and the nonidentity of the characteristics of the paraphase amplifiers. In addition, this device can operate only at a low frequency of the radio pulse at the input, since the minimum time between two successive radio pulses is determined mainly by the time taken to measure the voltage phase difference from the outputs of the resonant amplifiers. Due to the fact that the frequency of these voltages is small, the measurement time is large, it is necessary to limit the possible frequency of radio impulses from above.

The purpose of the invention is to increase the speed of measurement of the phases between the high-frequency filling of short radio pulses.

The goal is achieved by the fact that the proposed device for measuring the phase difference of radio pulses, containing two series-connected phase detectors and paraphase amplifiers, the input of the phase detectors connected via phase shifting circuits, includes N channels, each of which consists of a resistive totalizer and a comparison element, In this way, the inputs of the adders are connected to the outputs of the paraphase amplifiers, and their outputs are connected to the inputs of the comparison elements, respectively.

From the outputs of the comparison elements, the code value corresponding to the measured phase difference is removed. Due to the fact that the processing of the output signals of phase detectors is performed in parallel in all channels without conversion to a low frequency, the speed of the device is great and is determined mainly only by the element base used.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 - stress diagrams for his work.

The device contains phase detectors 1 and 2, phase-shifting circuits 3 and 4, paraphase amplifiers 5 and b, comparison elements 7, 8 and 9, resistive adders consisting of resistors R and R. The number of channels N consisting of resistive adders and elements comparison, is determined by the required resolution and is 180 °,

N

mr

where Y is the measurement discrete ..

Phase detectors 1 and 2, between the pairs of inputs of which are included the 45th phase-shifting circuits 3 and 4, are connected through the paraphase amplifiers 5 and 6 to the corresponding inputs of resistive adders, the outputs of which, in turn, are connected to the xsd elements of comparison 7, 8 and 9.

The device works as follows.

Each of the input radio signals, the phase difference “of which is necessary and meoit, is fed to one of the phase

detektivov directly, and on the other Phase detector cheoz - phase-moving circuit (3 or 4). In this case, at the outputs of phase detectors 1 and 2, video signals are obtained, whose amplitude is proportional to collect sin p. Paraphase amplifications provide for the generation of signals of the form and isinf, which then arrive at the corresponding inputs of resistive adders. The weighting coefficients of the resistive adders are determined by the required measurement discrete and the channel number. The output voltages of the adders are applied to the input of the comparison elements, and differential amplifiers with sufficient gain can be used as comparison elements. In practice, these threshold devices perform a comparison operation. The trigger threshold is set in the reference elements themselves.

The operation of the channels is explained in FIG. 2 voltage plots at the outputs of paraffan amplifiers, resistive adders and reference elements.

Let the maximum value of the voltage at the outputs of the elements of the comparison be the value of the i "code, and the minimum voltage be the value of the O code. The voltage value at the output of the comparison element of any channel is determined in each specific case by the magnitude of the signal taken from the output of the corresponding resistive adder. This signal is

V - and () - SF) - and. (H) p u, (y) R..C "f) Ri - p,

. If you apply signals and and Uj, (f) - cosf to the adder, then

Y .. sin W -PICo f

K + Ra

i.e., knowing the threshold value of the comparison element operation, by selecting the resistance of the resistors R and Rj, one can achieve the transfer of the comparison element from the state O to the code state at a predetermined value of the phase difference f (, i input signals. Reverse The transfer of the circuit (from state i to state O of the code) can occur, as can be seen from the diagrams in Fig. 2, only when the input phase difference is changed by 180, i.e. at% + 18 (f. Choosing resistive resistance values adders, it is possible to make the elements of comparison in each channel with predetermined values of the phase difference determined by the measurement discrete and channel number. In our example, the comparison element in the i-oM channel should work, i.e., 5 be transferred from state O to code state, with the value of the measured difference The phases H / L where T is the discrete dimension, 2, ..., N is the channel number. The addition -f- in this expression is defined as 1 | because in the example of the device realization the origin point (zero) is located in the middle of the discrete. The code value at the output of the channel i-oro comparison element exists at fi6V (fi -I80). during the measurement, a combination of code is created at the outputs of all elements of the comparison, uniquely related to the measured phase difference. In the diagrams below, the measurement is chosen to be 22.5 °, and the threshold for the operation of the comparison elements is zero. In this case, the first channel is triggered at “fall, 25, and the second at f 33.75, etc. As in any discrete systems, the phase characteristic of the proposed device has a stepped form, i.e. only one specific value of the measured phase difference fujM corresponds to a change in the input phase difference f within the discrete limits. In our example, the zero sampling corresponds to the region of the input phase difference from -11.25 to +11.25, i.e. point O is in the middle of the sample. If this is undesirable, then the zero point is simply enough to bring to the edge of the discrete. The first sampling, Te) 22.5 °, corresponds to the region of the input phase difference cf from 11.25 to 33.75, etc. In order for the voltage from the output of the adder to pass through O, which is the threshold of the comparison elements, it is necessary to apply to adders voltage opposite in sign. To comply with this condition, as is evident from the diagrams for resistive adders from 1 to j channels, for example, sinvpH cosvp, and for adders with (y- + 1) N channels, triggered in the range of the input phase difference J from f- to , n gives signals -cos-and -sinj. At this positive value, for example, the NIN at the output of the adder, corresponds to the code value at the output of the comparison element, and to the negative value - O code at the output of the comparison element. Other combinations of signals supplied to resistive channel adders are possible. In each particular case, the weighting factors (i.e., the resistance values of the resistors R, Rj) of the resistive adders in the channel are determined from the expression RaUi (). UaC) UTTOP R, + R4 where then the threshold value of the reference element triggered (preferably the average voltage assignment from the output of paraphasic amplifiers); fi is the phase difference of the input signals at which the reference element should be transferred in the i-OM channel from the state O to the state 1 code; Ul (V «), Ue (p) - voltages applied to the resistive adder of the i-oro channel. The plots shown in FIG. 2, all possible states of the indicated circuits are considered for different values of the measured phase difference and within the O-ZbO. In the measurement process, φ takes one specific value, which lies within the specified limits. In this case, the magnitude of the output voltage of the comparison element in each channel is determined by the signal taken from the output of the resistive cyMviaTopa of this channel, i.e. determined by this value of j. Thus, a combination of a single code corresponding to the measured phase difference is created at the outputs of all comparison elements. This code can be processed directly by a computer operating according to a given algorithm, or it can be converted into a usual binary or decimal code with the help of a transceiver. Below, as an example, code combinations at the output of the device are given for different values of the input phase difference. In the proposed example, the implementation of the device discretization measure 22,5, then the number of channels N G You can create the following code table.

Table